Dry-cast lightweight veneer block, system, and method

ABSTRACT

Described are dry cast lightweight veneer blocks and a system and method of installing lightweight veneer blocks. The courses can be assembled without mortar between the courses. As an example, sides of the veneer blocks have areas that recede from an imaginary plane between adjacent veneer blocks to give a deep texturing and a shadow effect between veneer blocks. The installation system and method include a substrate, an air barrier applied to the substrate, a plurality of veneer blocks, and an adhesive applied between the plurality of veneer blocks and the air barrier.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to and claims priority benefits from U.S.Provisional Application Ser. No. 62/185,395 (“the '395 application”),filed on Jun. 26, 2015, entitled “DRY-CAST LIGHTWEIGHT VENEER.” The '395application is hereby incorporated in its entirety by this reference.

FIELD OF THE INVENTION

This invention relates to dry-cast lightweight veneer products that areintended to adhere to other load bearing surfaces.

BACKGROUND

Wet-cast lightweight veneer products have been known in the industry forsome time, and are intended to resemble natural stone and other masonrymaterials in size, shape, and texture. Typically, the wet-castlightweight veneer products are wet-cast into handcrafted latex moldsusing a wet mixture of cement, supplementary cementitious materials,lightweight aggregates, chemical admixtures, and mineral oxide colorpigments. The lightweight veneer products are used as an adhered,non-load-bearing exterior veneer or interior wall finish. The units aredesigned for vertical applications and can be installed on any properlyprepared substrate such as concrete, masonry, drywall, or plywood.

To ensure quality, the wet-cast lightweight veneer products must complywith ASTM C1670. For example, according to ASTM C1670/C1670M—15 (Sep. 1,2015 ed.) 8.3.2, the weight per square foot of the unit shall bedetermined by multiplying the saturated density of the unit by theaverage thickness, and shall not exceed 15 lb/ft². ASTM C1670/C1670M—15(Sep. 1, 2015 ed.) 8.3.1 further provides a formula for calculating thesaturated density, in which the saturated weight of a specimen isdivided by the difference in the saturated weight and the immersedweight of the specimen. As a result, a higher absorption rate of thelightweight materials can negatively impact the ability of the productto meet the lightweight veneer requirements.

The lightweight aggregate used must meet the requirements of ASTM C330or C331. Expanded shale, clay, and slate (“ESCS”) typically meet theserequirements and is usually the aggregate that is used in the mixture.The wet-cast lightweight veneer products are structurally strong,physically stable, durable, environmentally inert, and light in weight.

To apply the coloring to the wet mixture, typically the latex mold islined with pigment and the mixture is introduced into the latex mold.Once the product dries and hardens, the latex mold is removed, and thepigment is then embedded into the surface of the wet-cast lightweightveneer product.

Because the pigmentation is only a surface treatment, any chips ordamage to the wet-cast lightweight veneer products means that theunpigmented inner portions are visible, resulting in a less than visiblypleasing appearance. Furthermore, the use of surface pigmentation meansthat the wet-cast lightweight veneer products cannot be acid washed, asthe acid wash removes the surface pigmentation, also exposing theunpigmented inner portions of the wet-cast lightweight veneer products.The use of surface pigmentation also means that the stone veneer cannotbe cut to fit a space because the exposed unpigmented concrete edge willshow.

In addition, because the wet-cast lightweight veneer products requirethe use of a latex (or other flexible) molds for removal afterhardening, the flexible nature of the mold results in some variation inshape among the various units. For example, when applying the product,each course must be leveled with mortar applied in between courses as abuffer to absorb the variations among units.

Furthermore, such lightweight veneer products are conventionallyinstalled using a multi-step system, as illustrated in FIG. 1. In thissystem, a weep screed is first attached to the bottom part of anexterior sheathing. Flashing is then applied over the sheathing,overlapping the vertical portion of the weep screed. Typically, weatherresistive barrier (“WRB”) is applied in two separate layers starting atthe bottom of the wall (overlapping the weep screed) and working upward,using staples to attach them to the wall. The WRB overlaps horizontally2″ to 4″ and vertically a minimum of 6″ in shingle fashion. A metal lathis then applied over the WRB layers in horizontal fashion andoverlapping 1″ to 2″ at both the horizontal and vertical seams. Using atrowel, mortar is spread over the entire lath, approximately ½″ to ¾″thick so that no lath material is visible. Once the mortar is thumbprinthard, a stiff bristle brush or scratch rake can be used in horizontalmotion to create a rough surface. After scratching the mortar, thescratch coat cures for 24-48 hours before installing veneer blocks. Toapply the veneer blocks, mortar is applied to the entire back surface ofthe veneer block to ensure adhesion to the scratch coat. The block ispressed firmly onto the scratch coat and slid back and forth slightlyuntil mortar squeezes out around the perimeter of the stone. Thisprocess is time-consuming and requires a skilled mason's expertise.

In certain embodiments, it may be desirable to produce a lightweightveneer product in which the pigmentation may be mixed throughout, andcan be produced using a process that would result in more precisedimensions. It may also be desirable to streamline the installationprocess for veneer blocks of all types in a way that would reduce thenumber of steps, reduce the time required, and/or reduce the skill levelneeded so that a larger labor pool may be used to install veneer blocksin a shorter period of time.

SUMMARY

The terms “invention,” “the invention,” “this invention” and “thepresent invention” used in this patent are intended to refer broadly toall of the subject matter of this patent and the patent claims below.Statements containing these terms should be understood not to limit thesubject matter described herein or to limit the meaning or scope of thepatent claims below. Embodiments of the invention covered by this patentare defined by the claims below, not this summary. This summary is ahigh-level overview of various aspects of the invention and introducessome of the concepts that are further described in the DetailedDescription section below. This summary is not intended to identify keyor essential features of the claimed subject matter, nor is it intendedto be used in isolation to determine the scope of the claimed subjectmatter. The subject matter should be understood by reference toappropriate portions of the entire specification of this patent, any orall drawings and each claim.

Certain embodiments of the present invention comprise a dry castlightweight veneer block. In some embodiments, pigmentation is dispersedthroughout the dry cast lightweight veneer block. In certainembodiments, a weight of the dry cast lightweight veneer block is lessthan or equal to 15 lb/ft². The protocol for measuring this value isdescribed in ASTM C1670/C1670M.

The dry cast lightweight veneer block may be formed from a dry castmixture comprising approximately 35-45% by weight lightweight aggregate.The dry cast mixture may further comprise approximately 25-35% by weightfine sand. In some embodiments, the dry cast lightweight veneer isformed in a steel mold.

Certain embodiments of the present invention comprise assembly of drycast lightweight veneer blocks, wherein courses of the dry castlightweight veneer blocks are assembled without mortar between thecourses. In some embodiments, sides of the dry cast lightweight veneerblocks comprise areas that recede from an imaginary plane betweenadjacent dry cast lightweight veneer blocks.

According to certain embodiments of the present invention, aninstallation system comprises a substrate, an air barrier applied to thesubstrate, a plurality of lightweight veneer blocks, and an adhesivelocated between the plurality of lightweight veneer blocks and the airbarrier.

In some embodiments, the air barrier has an adhesion value of at least16 psi. The substrate may be wood, plywood, exterior sheathing, orientedstrand board, drywall, chipboard, hardboard, cement board, concrete,blockwork, and fiber cement siding. In certain embodiments, a shearstrength of the bond between the plurality of lightweight veneer blocksand the air barrier is approximately 4000-5000 lb/ft².

In some embodiments, the plurality of lightweight veneer blocks are drycast lightweight veneer blocks and/or each have a weight of less than orequal to 15 lb/ft².

According to certain embodiments of the present invention, a method ofinstalling a plurality of lightweight veneer blocks on a substratecomprises applying an air barrier to the substrate, applying an adhesiveto the air barrier, and installing the plurality of lightweight veneerblocks in courses by pressing the plurality of lightweight veneer blocksagainst the adhesive. According to some embodiments, the method maycomprise applying an adhesive to the substrate, and installing theplurality of lightweight veneer blocks in courses by pressing theplurality of lightweight veneer blocks against the adhesive.

In some embodiments, applying the adhesive to the air barrier maycomprise applying the adhesive in beads positioned approximately 3-4inches apart. Applying the air barrier to the substrate may compriserolling or spraying a liquid air barrier onto the substrate.

According to some embodiments, the method is performed at aninstallation rate of 45-50 ft²/hr.

In some embodiments, the air barrier has an adhesion value of at least16 psi. The substrate may be wood, plywood, exterior sheathing, orientedstrand board, drywall, chipboard, hardboard, cement board, concrete,blockwork, and fiber cement siding. In certain embodiments, a shearstrength of the bond between the plurality of lightweight veneer blocksand the air barrier is approximately 4000-5000 lb/ft².

In some embodiments, the plurality of lightweight veneer blocks are drycast lightweight veneer blocks and/or each have a weight of less than orequal to 15 lb/ft².

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed description, embodiments of the invention aredescribed referring to the following figures:

FIG. 1 is a side cross-sectional view of a conventional veneer blockinstallation system with mortar joint spacing visible.

FIG. 2 is an image of an installed wall of dry-cast lightweight veneerblocks (“DCLV blocks”) with no mortar joints, according to certainembodiments of the present invention.

FIG. 3 is an image of an installed wall of DCLV blocks, according tocertain embodiments of the present invention.

FIG. 4 is an image of an installed wall of DCLV blocks, according tocertain embodiments of the present invention.

FIG. 5 is an image of a chimney formed with DCLV blocks, according tocertain embodiments of the present invention.

FIG. 6 is another image of the chimney of FIG. 5.

FIG. 7 is another image of the chimney of FIG. 5.

FIGS. 8A-8E are views of mold walls that form the deep shadowing sidetexturing of DCLV blocks, according to certain embodiments of thepresent invention.

FIG. 9 is a cross-sectional view of a mold that forms the deep shadowingside texturing of DCLV blocks, according to certain embodiments of thepresent invention.

FIG. 10 is a front view of a mold that forms a layout of DCLV blockswith deep shadowing side texturing, according to certain embodiments ofthe present invention.

FIG. 11 is a perspective view of the mold of FIG. 10.

FIG. 12 is an image showing an application of an adhesive to a curedsurface of an air barrier applied to a substrate, according to certainembodiments of the present invention.

FIG. 13 is an image showing installation of a first course of veneerblocks to the substrate of FIG. 12.

FIG. 14 is an image showing the drainage plane present between theveneer block and the substrate after installation of the veneer blocksto the substrate of FIG. 12.

FIG. 15 is an image of the substrate of FIG. 12 after several courses ofveneer blocks have been installed.

FIG. 16 is an image of the substrate of FIG. 12 after more courses ofveneer blocks have been installed.

FIG. 17 is an image of the opposing side of the substrate of FIG. 12.

FIG. 18A is a graph of air leakage test results at infiltration beforecycling for DCLV blocks installed with adhesive and air barrier on anOSB substrate, according to certain embodiments of the presentinvention.

FIG. 18B is a graph of air leakage test results at exfiltration beforecycling for DCLV blocks installed with adhesive and air barrier on anOSB substrate, according to certain embodiments of the presentinvention.

FIG. 18C is a graph of air leakage test results at infiltration aftercycling for DCLV blocks installed with adhesive and air barrier on anOSB substrate, according to certain embodiments of the presentinvention.

FIG. 18D is a graph of air leakage test results at exfiltration aftercycling for DCLV blocks installed with adhesive and air barrier on anOSB substrate, according to certain embodiments of the presentinvention.

DETAILED DESCRIPTION

The subject matter of embodiments of the present invention is describedhere with specificity to meet statutory requirements, but thisdescription is not necessarily intended to limit the scope of theclaims. The claimed subject matter may be embodied in other ways, mayinclude different elements or steps, and may be used in conjunction withother existing or future technologies. This description should not beinterpreted as implying any particular order or arrangement among orbetween various steps or elements except when the order of individualsteps or arrangement of elements is explicitly described.

Dry-Cast Lightweight Veneer Mix Design

The dry-cast lightweight veneer blocks (“DCLV blocks”) described belowand in the claims of this patent may be construction materialsmanufactured of any suitable dry cast materials, including but notlimited to cement, sand, and aggregates. In some cases, additionaland/or alternative ingredients may be used, which may include but arenot limited to other masonry products, structural foams, plastics,plastic composites, reinforced plastics, filled plastics, and polymermaterials. In certain embodiments, the mixture used to form the DCLVblocks may comprise course sand, fine sand, and lightweight aggregate.FIGS. 2-7 are images of certain embodiments of DCLV blocks installed inwalls and chimneys.

It will be understood that the term “fine sand” generally refers to sandin which the majority of particles have a particle size less than 600μm, and more specifically refers to sand in which over 70% of particleshave a particle size in a range of 300 μm-600 μm. Examples of fine sandinclude but are not limited to silica sand.

It will also be understood that the term “coarse sand” generally refersto sand in which the majority of particles have a particle size greaterthan 300 μm, and more specifically refers to sand in which over 60% ofparticles have a particle size in a range of 300 μm-2 mm. Examples ofcoarse sand include but are not limited to FA2 sand.

The lightweight aggregate may include but is not limited to gravelite,expanded shale, pumice, slag aggregate, etc.

A Fineness modulus (“FM”) is an empirical figure defined mathematicallyas the sum of the cumulative percentages retained on standard sievesdivided by 100. Standard size sieves are ⅜ in (9.5 mm), No. 4 (4.75 mm),No. 8 (2.36 mm), No. 16 (1.18 mm), No. 30 (600 μm), No. 50 (300 μm), andNo. 100 (150 μm). FM is an index of the fineness of an aggregate, thehigher the FM, the coarser the aggregate. In certain embodiments, finesand may have a FM of less than 2, and course sand may have a FM ofgreater than 2. However, these are merely ranges for certainembodiments, and other values outside these ranges may be included inboth categories.

The ratio of lightweight aggregate to the course and fine sand matrixresults in a density of 105 lb/ft³ or less, whereas traditional dry castproducts have a density of approximately 140-141 lb/ft³. The greaterdensity associated with dry-cast products has traditionally made it verydifficult to use dry-casting as a way to produce lightweight veneers,particularly since ASTM standards limit the maximum weight of veneers to15 lb/ft², a value easily attained with wet cast products due to thepredominance of lightweight aggregates.

For comparison, a DCLV block of 1⅝ in (nominal) thickness has overalldimensions of 1⅝ in×12 in×12 in (or 235.275 in³ or 0.136 ft³). A maximumdensity of the DCLV block at 15 lb/ft² is 110.17 lb/ft³. Table I belowshow the correlation between other densities for a DCLV block of thesedimensions.

TABLE I Correlation between other Densities for a DCLV Block. 105 lb/ft³14.296 lb/ft² 103 lb/ft³ 14.024 lb/ft² 101 lb/ft³ 13.752 lb/ft²  99lb/ft³ 13.479 lb/ft²

When lightweight aggregate was initially introduced into the dry castmixture during early testing, the lightweight aggregate tended todisperse to the surface of the DCLV blocks, giving it an undesirable“popcorn ceiling” appearance. To temper that look, the ratios of variousgradations of sand were evaluated to determine how to prevent themigration of the lightweight aggregate to the surface, while alsokeeping the weight from exceeding the threshold amount. To achieve thedesired balance of the conflicting properties, fine sand may be added tothe aggregate in a range of 25%-35% by weight, depending on graduationsof the other aggregates, to provide a tight texture. The lightweightaggregate may be added in a range of 35%-45% by weight, depending ongraduations and weight of the other aggregates, and may be added toensure that the blend has a maximum weight of 15 lb/ft². The protocolfor measuring this value is described in ASTM C1670/C1670M. In someembodiments, the amount of lightweight aggregate may be as low as 30% byweight. Coarse sand may be added as a filler in any suitable range thatprovides the appropriate weight and properties. The mixture of both fineand coarse sand allows the dry-cast product to achieve the necessaryweight below the ASTM maximum threshold value of 15 lb/ft², while alsoallowing the mixture to have a smooth surface appearance.

In certain embodiments, color pigmentation is added directly with theother ingredients to form the mixture, rather than adding it to thesurface of a mold. As a result, the coloration extends through theentire DCLV block, and chipping or damaging the surface of the DCLVblock does not reveal any unpigmented inner portions.

Likewise, the surface of the DCLV block can be cleaned like any standardmasonry without concern that such treatment will remove surfacepigmentation and expose unpigmented inner portions below.

To prepare the DCLV blocks, the mixture is prepared and introduced intoa steel mold. Pressure is then applied to the mixture with a shoe sothat the mixture hardens into the DCLV blocks. By forming the mold fromsteel (or other suitably rigid material), the DCLV blocks can be madewith a high level of precision, otherwise not possible with latex molds,urethane molds, or other flexible molds. The use of steel or otherwiserigid molds is not possible with wet cast concrete because there is noway to remove the wet cast product from the mold after it has dried andhardened.

EXAMPLES

32% by weight (1415 lb) silica sand, 27% by weight (1195 lb) FA2 sand,and 41% by weight (1810 lb) lightweight aggregate (gravelite) werecombined form a lightweight aggregate blend. The resulting particle sizedistribution is summarized in Table II below.

TABLE II Distribution in Particle Size within Each Component. SilicaSand FA2 Sand Gravelite Sieve Grams % % Grams % % Grams % % Size Ret.Ret. Accum Ret. Ret. Accum Ret. Ret. Accum ⅜″ 0.0 0.0% 0.0% 0.0 0.0%0.0% 0.0 0.0% 0.0% (9.5 mm) #4 0.0 0.0% 0.0% 1.6 0.2% 0.2% 25.2 7.6%7.6% (4.75 mm) #8 0.0 0.0% 0.0% 63.7 8.2% 8.4% 90.6 27.4% 35.1% (2.36mm) #16 0.0 0.0% 0.0% 109.2 14.1% 22.5% 88.3 26.7% 61.8% (1.18 mm) #308.6 1.0% 1.0% 191.8 24.8% 47.3% 55.6 16.8% 78.7% (600 μm) #50 656.076.7% 77.7% 168.8 21.8% 69.1% 30.8 9.3% 88.0% (300 μm) #100 183.8 21.5%99.2% 219.2 28.3% 97.4% 14.3 4.3% 92.3% (150 μm) Pan 6.5 0.8% 100.0%20.3 2.6% 100.0% 25.3 7.7% 100.0% Total 854.9 FM = 1.78 774.6 FM = 2.45330.1 FM = 3.64

A Hillcrest dry cast lightweight veneer product, which is also shown inFIGS. 2-7, was prepared according to the aggregate mixture. TheHillcrest product and a wet cast lightweight veneer product (known asEldorado Limestone) were comparatively tested for compressive strength,density, and absorption, according to AC51, ASTM C170, and ASTM C140.The compression of the Hillcrest product could not be tested inaccordance with ASTM C190, which is a wet cast standard. Also, thecylinder samples are smaller than required by ASTM C170 due to the stonethickness. AC51 requires 1800 psi minimum with a 10% maximum variation,22% maximum water absorption (for stones <85 lb/ft³), and 15% maximumwater absorption (for stones <125 lb/ft³). The test results for theEldorado Limestone Wet Cast Lightweight Veneer are included in Table IIIbelow; and the test results for the Hillcrest Dry Cast LightweightVeneer are included in Table IV below.

TABLE III Test Results for Eldorado Limestone Wet Cast LightweightVeneer. Absorp- Compressive Strength Density tion ASTM C170 ASTM C140MPa PSI Kg/m3 Lb/ft3 % # A 27.8 4032 1262 78.78 19.6 sam- B 27.4 39741261 78.72 19.6 ple C 33.7 4888 1261 78.72 18.6 D 32.0 4641 1260 78.6619.9 E 31.6 4583 1256 78.41 19.6 F 33.7 4888 1265 78.97 19.0 Average31.0 4501 1261 78.7 19.4 Min 27.4 3974 1256 78.4 18.6 Max 33.7 4888 126579.0 19.9 Std Dev 2.6 370 2.7 0.2 0.4 Ecart min 11.7% 0.4% 4.0% Ecartmax  8.6% 0.3% 2.7% Max var/avg   12% 0.4% 4.0%

TABLE IV Test Results for Hillcrest Dry Cast Lightweight Veneer. Absorp-Compressive Strength Density tion ASTM C170 ASTM C140 MPa PSI Kg/m3Lb/ft3 % # 1 44.9 6512 1697 105.94 6.0 sam- 2 34.4 4989 1656 103.38 6.0ple 3 35.0 5076 1666 104.00 6.1 4 44.1 6396 1664 103.88 5.8 5 45.4 65841700 106.13 6.1 6 45.7 6628 1691 105.57 5.6 7 32.8 4757 1647 102.82 5.7Average 40.3 5849 1674 104.5 5.9 Min 32.8 4757 1647 102.8 5.6 Max 45.76628 1700 106.1 6.1 Std Dev 5.5 794 19.7 1.2 0.2 Ecart min 18.7% 1.6%5.1% Ecart max 13.3% 1.5% 3.4% Max var/avg   19% 1.6% 5.1%

In these test results, the variation in the Hillcrest Dry CastLightweight Veneer and the Eldorado Limestone Wet Cast LightweightVeneer for compression tests is higher than required by AC51, butminimum results are still very high in comparison with the 1800 psiminimum. In fact, the dry cast veneer process generates products with4-5 times higher psi than the wet cast process, which is particularlynoticeable when compared to the AC51 standard, which sets a minimumlimit for psi at only 1800 psi and which was developed based on wet castveneer products.

The lower absorption rate/integral water repellent and higher psi valuesalso act to minimize freeze/thaw damage to the DCLV block. To confirm,the aggregate mixture was tested for freeze-thaw, according to ASTMC666/C666M and NQ 2624-120. Veneer specimens were prepared using theaggregate mixture and tested with the NQ2624-120 standard (except thatsalt water was replaced with fresh water) and ASTM C666/C666M.

Each specimen's resistance to freezing and thawing was tested. Accordingto the test protocol, the specimens must not break or disintegrate, andweight loss is limited to 3% of the original weight. Each specimen isprepared with a 4 inch square by a thickness of 1.63 inches, andsubjected to 50 cycles of freezing and thawing, unless the specimenbreaks or appears to have lost more the 1.5% of their original weight.Weight loss is determined as a percentage of the original weight of thedry specimens. The standard deviations of these tests are included inTable V below.

TABLE V Standard Deviations of Tests Performed. NQ 2624-120 ASTMC666/C666M Cycle 9.4.4.3 Total cycle 5.2 Total cycle time 2 h < durationtime 24 h t < 5 h Freezing Thawing duration > 25% 16 h +/− 1 h totalcycle time Thawing (procedure A) 8 h +/− 1 h Thawing duration > 20%total cycle time (procedure B) *Procedure A: rapid freezing and thawingin water Procedure B: rapid freezing in air and thawing in waterTemperature 9.4.2.1 5 to −15 deg C. 5.2 4 to −18 deg C. Immersing9.4.2.6 Salted water Unsalted water liquid * Replaced by fresh waterWeight loss 9.4.4   10-25-50 8.3 Intervals not exceeding measurementcycles 36 cycles to reach 300 cycles Means of 9.4.4   Filtering 8.3Scaling the specimen measuring and scaling itself weight loss particlesleft in the container

Deep Texturing for DCLV Blocks

In certain embodiments, deep texturing may be included within moldsurfaces, as best illustrated in FIGS. 8A-8E, 9, 10, and 11, so as toimpart an improved look of natural stone to the DCLV blocks, includingshadows and other effects. With such deep textures, many dry castproducts may have a tendency to stick to the textured areas. Despite thepresence of deep texturing in the mold, the DCLV block is typicallyeasily removed from the mold without the need for heat. In certainembodiments, it may nevertheless be desirable to introduce heat with themold to enhance removal of the DCLV blocks so that even greatertexturing may be achieved. Furthermore, each dry cast cycle produces9-11 square feet onto a board.

In certain embodiments, as shown in FIGS. 8A-8E, 9, 10, and 11, the moldmay be configured to apply textures to the face and/or to the sides ofthe DCLV block. In the case of the sides, the textures are arranged sothat the sides may have areas that recede from an imaginary plane withother areas that either align or contact the imaginary plane but do notexceed the imaginary plane. In some embodiments, the imaginary planes ofeach side may be arranged at approximately 90 degree angles from theimaginary plane of adjacent sides, thus forming a very precisely squaredouter perimeter of each DCLV block that also has a look and feel ofnatural stone. In other embodiments, the imaginary planes may bearranged at any suitable angle to form other precise shapes, includingbut not limited to hexagons, rectangles, triangles, octagons, pentagons,or any other curved or straight polygonal shape, including but notlimited to regular and irregular polygons.

By arranging the receded locations and the contact locations within aparticular side of the DCLV block strategically, the contract portionsof the DCLV are aligned with the imaginary planes and are positioned tocontact the contact portions of a mating side of an adjacent DCLV block.Since these contact portions are arranged substantially parallel to theimaginary outer plane, the DCLV blocks may be installed in very straightand level courses that do not require mortar to be applied betweencourses to achieve a level application.

Installation System For Lightweight Veneer Products

According to certain embodiments of the present invention, a system forinstalling DCLV block or any other stone or brick veneer blocks thatweighs 15 lb/ft² or less (collectively, referred to herein as “veneerblock”) comprises the use of an air barrier and an adhesive to attachthe block to a substrate.

Examples of substrates may include but are not limited to wood, plywood,exterior sheathing, oriented strand board (“OSB”), drywall (also knownas plasterboard, wallboard, gypsum board, Sheetrock, Gyproc,plasterboard), chipboard, hardboard, cement board, concrete, blockwork,and fiber cement siding.

In certain embodiments, the air barrier may be any substance used tostop unrestricted air infiltration and exfiltration through a buildingenvelope, which adheres directly to the substrate such that greater than16 psi of force is required to separate the air barrier from thesubstrate, as measured according to ASTM D4541. Examples of suitable airbarriers that meet these parameters may include but are not limited toExoAir ® 230, which is a fluid-applied vapor-permeable air barriermembrane manufactured by Tremco illbruck.

In certain embodiments, the adhesive may be any substance that providesa high strength flexible bond between the block and the air barrier witha shear strength of approximately 4000-5000 lb/ft². The adhesive may bea blend of polymers (including but not limited to acrylic, latex, andurethane polymers) and adhesion promoters, which are compatible with theair barrier composition, and have good adhesion to a variety ofconstruction surfaces including but not limited to brick, concrete,wood, plywood, exterior sheathing, OSB, drywall (also known asplasterboard, wallboard, gypsum board, Sheetrock, Gyproc, plasterboard),chipboard, hardboard, cement board, concrete, blockwork, and fibercement siding. Furthermore, the adhesive may have an “instant grab” thatminimizes the need for additional clamping or other mechanical supports,while still allowing some initial sliding of the block for placementduring installation. In addition, the adhesive may have a shore Ahardness of at least 50. The adhesive may further have a sufficientlyhigh viscosity that prevents the adhesive from completely flatteningwhen applied in vertical beads to the substrate so as to ensure that adrainage plane between the veneer block and the substrate remains open,as described in more detail below.

Examples of suitable adhesives that meet these parameters may includebut are not limited to SP350, which is hybrid polymer sealant andadhesive based on Tremco illbruck's advanced SP hybrid polymerformulation. In other embodiments, the adhesive may be in the form of atape applied to the cured surface of the air barrier.

In certain embodiments, to install the blocks, the substrate is firsttreated (or may be pre-treated) with the air barrier. FIG. 12illustrates such a substrate, in this example OSB, which has beentreated with a fluid air barrier. Treatment may include rolling orspraying the air barrier onto the substrate. Once the air barrier hascompletely cured, a starter wood stud may be fastened to the bottom ofthe substrate for alignment and to prevent the veneer blocks fromsliding during installation, also as illustrated in FIG. 12. Theadhesive is then applied in relatively small sections (around 3 ft²) tothe cured air barrier surface using beads of adhesive spacedapproximately every 3-4 inches. In some embodiments, the adhesive may beapplied directly to the substrate, such as in applications were an airbarrier is not needed. The adhesive may be applied using a caulk gun,and may further be applied with a caulk gun having two applicators sothat two beads of adhesive may be applied simultaneously.

Once the adhesive has been applied within a section of the substrate,the veneer blocks may be pressed against the adhesive in courses, asbest illustrated in FIGS. 13, 15, 16. Because of the adhesive hardnessand the spacing between beads, the adhesive compresses down toapproximately a ⅛ inch thickness, thereby forming a drainage planebetween the veneer block and the substrate. This drainage plane is bestillustrated in FIG. 14.

In certain cases, the adhesive installation system is an improvementover conventional installation methods (as described in the backgroundsection and shown in FIG. 1) because it may eliminate the need for usingmultiple layers of weather resistive barrier that are attached to thesubstrate with staples, using a metal lath over the weather resistivebarrier so that a mortar coat can be applied to the substrate, and usingmortar to install the veneer blocks. As a result, using the adhesiveinstallation system, a two-person crew can install at least 135 ft² inthree hours (equivalent to approximately 45 ft²/hr) and may furtherinstall approximately 150 ft² in three hours (equivalent toapproximately 50 ft²/hr). Using a conventional installation system, asdescribed in the background section and shown in FIG. 1, a typicalinstallation rate is approximately 10 ft²/hr with a two-person crew).Thus, in certain embodiments, the adhesive installation system is atleast 3.5 times faster, and may be as much as 4-5 times faster, thanconventional installation systems, while still providing a finalinstalled product that meets or exceeds industry veneer installationstandards.

Another advantage is that the skill set needed for the presentinstallation system is not necessarily limited to skilled masons. Apainter or other similarly skilled laborer can apply the air barrier tothe substrate and apply the adhesive to the cured air barrier surface,as well as adhere courses of veneer blocks to the substrate.

EXAMPLES

To test the installation system, wall was constructed with 7—2″×4″×8′wooden studs secured onto a top and bottom 2″×4″×8′ wood stud plate with3″ penny nails. As a result, the test area was 5.946 m². The wall wasthen screwed into a 2″×12″ SFP wooden buck. ½″ OSB was then attachedhorizontally to the exterior with 3″ penny nails spaced approximatelyevery 8″ around the perimeter and 12″ up each stud. The OSB board jointwas then detailed with Dymonic 100 polyurethane sealant, then 75wet-mils of ExoAir 230 air barrier was applied to the exterior. Once themembrane was completely cured, DCLV blocks were attached to the exteriorwith lines of Tremco illbruck SP350 adhesive spaced approximately every3″. A starter 2″×4″ wood stud was fastened to the bottom of the buck toprevent the stones from sliding during installation. All sealants andadhesives were allowed to cure, and the 2″×4″ wood stud started wasremoved before the start of testing.

Tests performed on the wall included: Pre-E2357 air leakage test perE283—1015-001; Wind load conditioning per E2357—1015-002; Post-E2357 airleakage test per E283—1015-003; Deflection test per E2357—1015-004; 15min 137 Pa water leakage test per E331—1015-005; and 2 hour 300 Pa waterleakage test per IBC 1403.2—1015-006.

Test Conditions: Test Temperature at Start(° F.): 67.912; TestTemperature at End (° F.): 69.733; Average Temperature (° F.): 68.492;Avg. Barometric Pressure (in. Hg): 30.415. Water penetration passed 2hours at 300Pa (6.27 psf). The air leakage test results are summarizedin Table VI below. Additional test results for the air leakage are shownin FIGS. 18A-18D.

TABLE VI Test Results. Assembly Air Leakage Values @ 75 Pa (1.57 psf)Air Leakage Area Leakage Rate Pre-Conditioning Infiltration 0.04 L/s(0.09 cfm) 0.007 L/s · m² (0.001 cfm/ft²) Pre-Conditioning Exfiltration0.03 L/s (0.07 cfm) 0.006 L/s · m² (0.001 cfm/ft²) Post-ConditioningInfiltration 0.04 L/s (0.08 cfm) 0.006 L/s · m² (0.001 cfm/ft²)Post-Conditioning Exfiltration 0.04 L/s (0.09 cfm) 0.007 L/s · m² (0.001cfm/ft²)

Different arrangements of the components depicted in the drawings ordescribed above, as well as components and steps not shown or describedare possible. Flexibility in design and construction of components, andof assemblies of components, are among the hallmarks of this invention,so many components and structures in addition to those depicted anddescribed here are possible. Similarly, some features andsubcombinations are useful and may be employed without reference toother features and subcombinations. Embodiments of the invention havebeen described for illustrative and not restrictive purposes, andalternative embodiments will become apparent to readers of this patent.Accordingly, the present invention is not limited to the embodimentsdescribed above or depicted in the drawings, and various embodiments andmodifications can be made without departing from the scope of the claimsbelow.

1-24. (canceled)
 25. A block comprising: a dry cast mixture comprisingapproximately 35-45% by weight lightweight aggregate and approximately25-35% by weight fine sand and resulting in a dry cast veneer blockhaving a weight less than or equal to 15 lb/ft².
 26. The block of claim25, wherein pigmentation is dispersed throughout the block.
 27. Theblock of claim 25, wherein the block is formed in a steel mold.
 28. Anassembly of blocks of claim 25, wherein courses of the blocks areassembled without mortar between the courses.
 29. The assembly of claim28, wherein sides of the blocks comprise areas that recede from animaginary plane between adjacent blocks.
 30. An installation systemcomprising: a substrate; an air barrier applied to the substrate; aplurality of dry cast lightweight veneer blocks, each have a weight ofless than or equal to 15 lb/ft²; and an adhesive located between theplurality of lightweight veneer blocks and the air barrier.
 31. Theinstallation system of claim 30, wherein the air barrier has an adhesionvalue of at least 16 psi.
 32. The installation system of claim 30,wherein the substrate is wood, plywood, exterior sheathing, orientedstrand board, drywall, chipboard, hardboard, cement board, concrete,blockwork, and fiber cement siding.
 33. The installation system of claim30, wherein a shear strength of the bond between the plurality oflightweight veneer blocks and the air barrier is approximately 4000-5000lb/ft².
 34. A method of installing a plurality of blocks of claim 25 ona substrate, the method comprising: applying an air barrier to thesubstrate; applying an adhesive to the air barrier; and installing theplurality of blocks in courses by pressing the plurality of blocksagainst the adhesive.
 35. The method of claim 34, wherein applying theadhesive to the air barrier comprises applying the adhesive in beadspositioned approximately 3-4 inches apart.
 36. The method of claim 34,wherein applying the air barrier to the substrate comprises rolling orspraying a liquid air barrier onto the substrate.
 37. The method ofclaim 34, wherein the method is performed at an installation rate of45-50 ft²/hr.
 38. The method of claim 34, wherein the air barrier has anadhesion value of at least 16 psi.
 39. The method of claim 34, whereinthe substrate is wood, plywood, exterior sheathing, oriented strandboard, drywall, chipboard, hardboard, cement board, concrete, blockwork,and fiber cement siding.
 40. The method of claim 34, wherein a shearstrength of the bond between the plurality of blocks and the air barrieris approximately 4000-5000 lb/ft².
 41. A method of installing aplurality of blocks of claim 25 on a substrate, the method comprising:applying an adhesive to the substrate; and installing the plurality ofblocks in courses by pressing the plurality of blocks against theadhesive.